What do the abbreviations on a Tamron lens mean?
AD
AD is a special type of glass and it stands for Anomalous Dispersion. Tamron uses this type of glass to prevent chromatic aberration and to control light beams.
ASL
ASL means Aspherical Lens Elements. These are aspherical lens elements, that reduce lens deviations. Thanks to these elements, the design of the lens is lighter and more compact.
Di / Di II / Di III
Digital Integrated. The Di lenses are designed for all types of digital SLR cameras. Di II lenses are suitable for SLR cameras with an APS-C sensor. The Di III lenses are only compatible with Sony mirrorless cameras with an E mount.
FTM
FTM means Full Time Manual focus, which means you can also focus manually in the automatic focus mode. This way, you don't have to switch to the manual focus.
HID
High Index, High Dispersion. This refers to high-end compact lens elements, which prevents chromatic aberration. The lens elements are mainly used for telephoto lenses.
HLD
The abbreviation HLD means High/Low torque-modulated Drive. This new autofocus motor was introduced by Tamron in 2017. With this autofocus motor, you can accurately focus and you can take over the focus manually when you're in the autofocus mode.
IF
A lens with IF has Inner Focus. With these lenses, only the inner lens group moves when focusing, so the physical length of the lens doesn't change.
LD
Low Dispersion lens elements are used to reduce chromatic aberration. Chromatic aberration looks like purple lining around details with a lot of contrast.
MR
MR stands for Moisture Resistant, which means the lens is dust proof and splash proof.
PZD
Piezo Electric Drive. A silent fast and accurate autofocus mode. This motor is smaller than many other autofocus motors.
SP
SP indicates the best Tamron lenses. The abbreviation stands for Super Performance, which means the lenses offer the highest image quality, because they contain high-end lens elements.
USD
USB is an Ultra Drive autofocus motor. This autofocus motor uses ultrasonic sound waves. This provides a very fast, silent, and accurate autofocus.
VC
If the lens says VC, it has Vibration Compensation. This system compensates vibrations that cause motion blur.
XLD
Extra Low Dispersion refers to special lens elements of Tamron that reduce chromatic aberration and color distortion to a minimum.
XR
Extra refractive. This refers to extra compact lens elements that correct image distortion.